HBM load cells for potentially explosive areas

Type examination certificates for load cells from HBM for use in potentially explosive areas have been reconfirmed.

Due to the great number of highly flammable materials, devices and protective systems for use in Europe in potentially explosive atmospheres must meet the requirements of directive 94/9/EC (ATEX 95) (in effect since July 1, 2003). One of the main changes to this directive was the separate evaluation of risks that are caused by mechanical ignition sources and the new evaluation and designations for potentially explosive dust zones.

The use for all potentially explosive areas has been reconfirmed for almost all HBM load cell types by the current type examination certificate issued. It covers device group I (devices used in mining) as well as device group II with categories 1, 2 and 3, corresponding to zones 0, 1, 2, 20, 21 and 22.

In addition to this reconfirmation, load cells of type C16 obtained an additional IECEx certificate: the degree of protection for flameproof encapsulation Ex d IIC T6 for use in potentially explosive atmospheres. This means that export outside the EU is possible. As normal weighing indicator are usually installed outside of the potentially explosive atmosphere, flameproof load cells do not require any additional safety components and can therefore be installed easily and without great expense.

HBM received the first ATEX type examination certificates in 2001, two years before the directive came into force. The oldest certificates can be traced back to 1966. HBM load cells are now at the latest stage of development, both at the European standardization level and at the level required for IEC standards, with this new type examination certificate.